A 型GPS􀀁OEM 板定位精度综合测试

通过进行两种型号的GPS接收机在静态和动态条件下的对比测试，分析得到了A型GPS-OEM接收机的数据采集时间、距基站距离对定位精度的影响规律，并测定了该型接收机的面积测量精度。因此得出，该型接收机能够满足1 ：1万底图的土地变更调查的界址点和面积量算的精度要求。     

P systems with active membranes and without polarizations

P systems with active membranes but without using electrical charges (polarizations) are shown to be complete for generating recursively enumerable string languages when working on string objects and using only rules with membrane transitions as well as rules with membrane dissolving and elementary membrane division, but also when using various other kinds of rules, even including a new type of rules allowing for membrane generation. In particular, allowing for changing membrane labels turns out to be a very powerful control feature.     

Multivariate predictions of local reduced‐order‐model errors and dimensions

This paper introduces multivariate input‐output models to predict the errors and bases dimensions of local parametric Proper Orthogonal Decomposition reduced‐order models. We refer to these mappings as the multivariate predictions of local reduced‐order model characteristics (MP‐LROM) models. We use Gaussian processes and artificial neural networks to construct approximations of these multivariate mappings. Numerical results with a viscous Burgers model illustrate the performance and potential of the machine learning‐based regression MP‐LROM models to approximate the characteristics of parametric local reduced‐order models. The predicted reduced‐order models errors are compared against the multifidelity correction and reduced‐order model error surrogates methods predictions, whereas the predicted reduced‐order dimensions are tested against the standard method based on the spectrum of snapshots matrix. Since the MP‐LROM models incorporate more features and elements to construct the probabilistic mappings, they achieve more accurate results. However, for high‐dimensional parametric spaces, the MP‐LROM models might suffer from the curse of dimensionality. Scalability challenges of MP‐LROM models and the feasible ways of addressing them are also discussed in this study.     

Day of the week submission effect for accepted papers in Physica A,PLOS ONE,Nature and Cell

The particular day of the week when an event occurs seems to have unexpected consequences. For example, the day of the week when a paper is submitted to a peer reviewed journal correlates with whether that paper is accepted. Using an econometric analysis (a mix of log–log and semi-log based on undated and panel structured data) we find that more papers are submitted to certain peer review journals on particular weekdays than others, with fewer papers being submitted on weekends. Seasonal effects, geographical information as well as potential changes over time are examined. This finding rests on a large (178,000) and reliable sample; the journals polled are broadly recognized (Nature, Cell, PLOS ONE and Physica A). Day of the week effect in the submission of accepted papers should be of interest to many researchers, editors and publishers, and perhaps also to managers and psychologists.     

Towards Behavioral Maude: Behavioral Membership Equational Logic

How can algebraic and coalgebraic specifications be integrated? How can behavioral equivalence be addressed in an algebraic specification language? The hidden-sorted approach, originating in work of Goguen and Meseguer in the early 80's, and further developed into the hidden-sorted logic approach by researchers at Oxford, UC San Diego, and Kanazawa offers some attractive answers, and has been implemented in both BOBJ and CafeOBJ. In this work we investigate both further extensions of hidden logic, and an extension of the Maude specification language called BMaude supporting this extended hidden-sorted semantics.Maude's underlying equational logic, membership equational logic, generalizes and increases the expressive power of many-sorted and order-sorted equational logics. We develop a hidden-sorted extension of membership equational logic, and give conditions under which theories have both an algebraic and a coalgebraic semantics, including final (co-)algebras. We also discuss the language design of BMaude, based on such an extended logic and using categorical notions in and across the different institutions involved. We also explain how Maude's reflective semantics provides a systematic method to extend Maude to BMaude within Maude, including module composition operations, evaluation, and automated proof methods.     

Stable and convergent iterative feedback tuning of fuzzy controllers for discrete-time SISO systems

This paper proposes new stability analysis and convergence results applied to the Iterative Feedback Tuning (IFT) of a class of Takagi–Sugeno–Kang proportional-integral-fuzzy controllers (PI-FCs). The stability analysis is based on a convenient original formulation of Lyapunov’s direct method for discrete-time systems dedicated to discrete-time input affine Single Input-Single Output (SISO) systems. An IFT algorithm which sets the step size to guarantee the convergence is suggested. An inequality-type convergence condition is derived from Popov’s hyperstability theory considering the parameter update law as a nonlinear dynamical feedback system in the parameter space and iteration domain. The IFT-based design of a low-cost PI-FC is applied to a case study which deals with the angular position control of a direct current servo system laboratory equipment viewed as a particular case of input affine SISO system. A comparison of the performance of the IFT-based tuned PI-FC and the performance of the PI-FC tuned by an evolutionary-based optimization algorithm shows the performance improvement and advantages of our IFT approach to fuzzy control. Real-time experimental results are included.     

用于水厂微水头发电的灯泡贯流式水轮机开发

在自来水供水过程中,存在着一些依靠水位差进行自流供水的环节。随着常规水能资源逐渐被开发殆尽,利用这部分微水头进行发电受到了关注。由于水厂工况基本不变、装置场地复杂多样等原因,常规水轮机并不适用,因此,开发新型水轮机就势在必行。结合某自来水厂安装灯泡贯流式水轮机进行发电的案例,通过传统水轮机设计理论对其进行设计,并运用计算流体动力学软件,选择SIMPLEC算法,采用基于雷诺平均N-S方程的Spalart-Allmaras湍流模型对该水轮机进行数值模拟和优化,得出在不影响水厂原有水处理工艺的前提下,在水厂安装水轮发电机组利用微水头进行发电从而达到节能减排目的的较优方案。     

Z‐BAG: A CLASSIFICATION ENSEMBLE SYSTEM WITH POSTERIOR PROBABILISTIC OUTPUTS

Ensemble systems improve the generalization of single classifiers by aggregating the prediction of a set of base classifiers. Assessing classification reliability (posterior probability) is crucial in a number of applications, such as biomedical and diagnosis applications, where the cost of a misclassified input vector can be unacceptable high. Available methods are limited to either calibrate the posterior probability on an aggregated decision value or obtain a posterior probability for each base classifier and aggregate the result. We propose a method that takes advantage of the distribution of the decision values from the base classifiers to summarize a statistic which is subsequently used to generate the posterior probability. Three approaches are considered to fit the probabilistic output to the statistic: the standard Gaussian CDF, isotonic regression, and linear logistic. Even though this study focuses on a bagged support vector machine ensemble (Z ‐bag), our approach is not limited by the aggregation method selected, the choice of base classifiers, nor the statistic used. Performance is assessed on one artificial and 12 real‐world data sets from the UCI Machine Learning Repository. Our approach achieves comparable or better generalization on accuracy and posterior estimation to existing ensemble calibration methods although lowering computational cost.     

拉萨河流域潜在蒸散发的气象因子敏感性

蒸散发可以反映气候变化对水资源的影响状况,根据拉萨河流域两个站点1955-2018年的逐日气象数据,采用FAO-56-Penman-Monteith公式计算潜在蒸散发(ET_0),进而采用敏感性分析、Mann-Kendall趋势检验、气候倾向率及小波分析等方法对拉萨河流域ET_0的变化特征及其影响因素进行分析。对比两个站点的变化规律,结果表明:流域ET_0整体对最高温度最为敏感,最高温度的贡献率最大,气象因子的敏感系数年内变幅为相对湿度最高温度风速日照时数最低温度;流域ET_0的日变化趋势为每10年增加0.03 mm,Mann-Kendall检验流域ET_0增长并不显著;流域的ET_0在25～30a尺度上周期振荡明显,出现了7次循环交替。